1. Field of the Invention
This invention relates to a screwdriver and screw, and more particularly, to a screwdriver designed for use with a screw having built-in notches or indents around the circumference of the screw head.
2. Description of Related Art
Various types of power or manual screwdrivers have been developed to increase work productivity. They come in various sizes and styles, but with one common shortfall. That is, almost all of them require an operator to manually hold a screw when using the screwdriver. The inconvenience of holding each screw is compounded since the work productivity is directly related to the rate of screws installed into work surfaces.
In addition, conventional screwdrivers are designed to engage a screw only in a bit receptacle formed on the head of the screw. For instance, a Phillips screwdriver is used for a bit receptacle having a cross shape. This may be problematic when the bit receptacle becomes mutilated due to excessive wear and tear. This problem is compounded when a screw is made with softer metal which is more susceptible to mutilation and disformation. In such cases, the screwdriver bit rotates in the bit receptacle of the screw without engaging and transferring the rotating force to the screw. Such action further mutilates the bit receptacle of the screw rendering the screw unusable, and thus, necessitating the mutilated screw to be replaced with a new one.
The mutilation of the head of a screw is also problematic when one needs to unscrew the screw from a work surface. Because the only source for transferring the rotating force from the screwdriver to screw is disfigured, the screw cannot be rotated and must be extracted from the working surface using other forceful means which may destroy the integrity of the work surface.
Certain screwdrivers have various means for holding a screw while screwing the screw into a work material, such as wood. Such screw holding devices do not provide a means for securely holding a screw head against a driving bit to prevent slippage of the bit from the screw head. To use such screwdrivers, a user must apply substantial pressure on the screwdriver handle to force the screw into a work material. Such pressure can result in a penetration of a screw at an undesired offset angle.